jbmurphy.com

I been wanting to write functions that act differently depending on how they were called. I am not sure if this is good practice or not, but I like the idea. Turns out all you need is “$MyInvocation.InvocationName” Look at they following code:

Function Test-Calling {
if ($MyInvocation.InvocationName -eq "cows"){Write-host "This function was called by an alias ($($MyInvocation.InvocationName))"}
if ($MyInvocation.InvocationName -eq $MyInvocation.MyCommand){Write-host "This function was called by name ($($MyInvocation.MyCommand))"}
}
set-alias cows Test-Calling

If you call the function by alias you get : This function was called by an alias (cows)
If you call the function by it’s name you get: This function was called by name (Test-Calling)

I hope that helps someone.

I was not happy with the code I wrote in this post. The goal was to write my functions with a “generic” naming convention, and then “process them” – change the naming convention to match my employer’s company name. For example JBMURPHY-AD-GetCurrentSite would be “processed” to Company-AD-GetCurrentSite. In the previous post, I just looped thought and created an alias for each function that matched a RegEx.

I think figured out a better way. Instead of creating aliases, I read the contents of the script line by line, replacing strings as I go, and then create a new file with the new naming conventions.

First I created a hash table with my search and replace strings:

	$SearchAndReplace = @{
	"JBMURPHY-" = "COMPANY-";
	"server.domain.com" = "realservername.company.com";
	}

Next I loop through the files, get their content line by line, loop through the hash table replacing the matching text and output to a temp file.

      foreach ($file in $(gci $SourcePath)) {
    	$tempFile = [System.IO.Path]::GetTempFileName()
    	get-content $file | %{
    	$OutPut=$_
    	ForEach ($key in $SearchAndReplace.Keys) {
    	  $OutPut=$OutPut -Replace $key,$SearchAndReplace[$key]
    	}
    	$OutPut >> $tempFile
    	}
    	move-item $tempFile $destination -force
    	}

Much cleaner, and I can keep adding search and replace terms to my hash table.

I have a naming convention for all the function that I write, for example: JBMURPHY-AD-GetGroup. I wanted to create aliases for all my functions with my employers’s name, for example CompanyName-AD-GetGroup. I created the following function to “grep” all the function names and create an “Alias” file. This file would have all the set-alias commands that would be sourced on PowerShell start up. This function contains Regular Expressions (my weakness), which I borrowed from here.

FUNCTION JBMURPHY-CreateAliases{
PARAM($OLDNAME="JBMURPHY-",$NEWNAME="CompanyName-")
$tempFile = [System.IO.Path]::GetTempFileName()

Select-String -Pattern "function\s+(\w+-\w+-\w+)\b" *.ps1 | %{
$FUNCTIONS=$_.Matches | %{$_.groups[0].Value -Replace "Function ",""}
Write-host "set-alias $($FUNCTIONS -Replace $OLDNAME,$NEWNAME) $FUNCTIONS -Option AllScope"
Out-File $tempFile -encoding ascii -append -inputobject "set-alias $($FUNCTIONS -Replace $OLDNAME,$NEWNAME) $FUNCTIONS -Option AllScope"
}
move-item $tempFile "$($NEWNAME)ALIASES.ps1" -force
}